A series of experiments, using a selective adaptation procedure, investigated some of the properties of the linguistic feature detectors that mediate the perception of the voiced and voiceless stop consonants. The first experiment showed that these detectors are centrally rather than peripherally located, in that monotic presentation of the adapting stimulus and test stimuli to different ears resulted in large and reliable shifts in the locus of the phonetic boundary. The second experiment revealed that the detectors are part of the specialized speech processor, inasmuch as adaptation of a voicing detector (as measured by a shift in the phonetic boundary) occurred only when the voicing information was presented in a speech context. In the third experiment, the detector mediating perception of the voiced stops was shown to be more resistant to adaptation than the detector mediating perception of the voiceless stops.